1. Field of the Invention
The present invention relates to a compact zoom lens composed of a plurality of lenses.
2. Description of the Related Art
A known zoom lens having a high zoom ratio about three is constructed by negative, positive and negative lens groups as shown in Japanese Patent Application Laying Open (KOKAI) Nos. 64-72114 and 2-63007.
However, the zoom lens disclosed in Japanese Patent Application Laying Open No. 64-72114 has a problem that chromatic aberration with respect to magnification is large.
In the zoom lens disclosed in Japanese Patent Application Laying Open No. 2-63007, a third lens group is constructed by four lenses arranged respectively in the order of a convex lens, a concave lens, a concave lens and a convex lens, and accordingly the zoom lens makes it possible to correct chromatic aberration with respect to magnification, but requires as many as four pieces of lenses. Furthermore, the zoom lens includes a fourth lens group in which a convex lens is arranged as the last lens of the fourth lens group, and consequently the fourth lens group becomes large in its size.